Response Time variable
Hi,
I would really like to know how the variable response time in the output file is computed.
Particularly, my experiment is made of by this sequence of elements:
-fixation cross
-stimulus display
-blank screen (until response)
-response to trial
-logger
Is the variable response time recorded by the logger at the end of each trial the time from the blank sceen onset until response? Or it is computed in another way?
Thank you in advance
Comments
Hi,
Response time is computed like this:
var.resp_time = var.response_time - var.time_keyboard_response
So, in your example the line "response to trial" is the important one. Depending on whether you use a mouse or keyboard response the item is different, but the procedure is the same. The start time is once the item is called, the end time is when the response is given. The difference between the two is the response time.
Is the variable response time recorded by the logger at the end of each trial the time from the blank sceen onset until response?
So, no, that would not be the response time. But the response time + the blank duration.
Hope this clears things up.
Eduard
Hi @eduard ,
I'm sorry, but I do not really get your point.
Actually, my partecipants have to respond pressing a key while the blank screen is being presented.
So, in my output file, the response time variable matchs with the max duration of the blank screen when they do not manage to answer. Differently, it has different values depending of participants' speed of response when they manage to respond.
Are not these values the response from the onset of the blank screen until the key be pressed, such as their reaction times?
Indeed, the column response time perfectly corresponds with the column of response to trial in my output file.
Thank you in advance
Are not these values the response from the onset of the blank screen until the key be pressed, such as their reaction times?
Only if the duration of the sketchpad with the blank screen is set to
0If you share your experiment I can try to point out why in your case it seems to be the duration from blank onset to response that is used as response time. Nevertheless, the way Opensesame computes response times is independent of any sketchpads. It only uses the keyboard response items in the way that I described above.
Eduard
Hi @eduard,
Yes, the duration of the blank display has been set to 0.
Thank you for everything!